Development of a fluorescence lifetime-based sol–gel humidity sensor

• Published in: Analytica chimica acta Vol. 570; no. 1; pp. 15 - 20
• Main Authors: McGaughey, Orla, Ros-Lis, José Vicente, Guckian, Adrian, McEvoy, Aisling K., McDonagh, Colette, MacCraith, Brian D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 07.06.2006; Elsevier
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Atmospheric pollution; Chemistry; Exact sciences and technology; Fluorescence lifetime; General, instrumentation; Pollution; Relative humidity; Sensor; Sol–gel; Spectrometric and optical methods; Relative humidity; Fluorescence lifetime; Sol–gel; Sensor; Performance evaluation; Oxygen; Sol-gel; Optical sensor; Air quality; Ruthenium II; Chemical sensor; Fluorescence spectrometry; Lifetime; Sensitivity; Humidity effect; Sol gel process; Detection limit; Monitoring; Ruthenium complex
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2006.03.113

A sol–gel-based optical sensor for the measurement of relative humidity has been developed. It is based on the changes in fluorescence intensity and/or lifetime of the ruthenium complex, ruthenium(II)diphenylphenanthroline-dipyridophenazinehexafluorophosphate. Sensitivity to relative humidity has been demonstrated over the range 0–100% relative humidity. This sensor has been developed for application in the field of indoor air-quality monitoring and displays a limit of detection of 0.35% relative humidity and a resolution of 1.13% over the concentration range of interest (0–50% relative humidity). The effects of varying process parameters on the sensor performance were studied along with the effects of cross-sensitivity to molecular oxygen.